A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae

A61B17/7002—Longitudinal elements, e.g. rods

A61B17/7019—Longitudinal elements having flexible parts, or parts connected together, such that after implantation the elements can move relative to each other

A61B17/7026—Longitudinal elements having flexible parts, or parts connected together, such that after implantation the elements can move relative to each other with a part that is flexible due to its form